1. Field of the Invention
The present invention relates to magnetic heads and, more particularly, to magnetic heads of a perpendicular magnetic recording type.
2. Description of the Related Art
A magnetic field sensor using antiparallel coupled magnetic films has been described in Japanese Patent Document 1 as a prior art reference. It has been discussed in Non-Patent Document 1 that antiparallel coupling takes place in multilayers or sandwich layers of Fe/Cr, Fe/Cu, Co/Cr, Co/Ru, and the like. A magnetic multilayer consisting of multiple layers of soft magnetic films and a magnetic head in which such a magnetic multilayer is employed to constitute a magnetic pole or a yoke have been described in Japanese Patent Document 2 as a prior art reference. A spin-valve sensor using antiferromagnetically coupled films has been described in Japanese Patent Document 3 as a prior art reference.
[Japanese Patent Document 1]
Japanese Unexamined Patent Application Publication No. Hei 2-61572
[Japanese Patent Document 2]
Japanese Unexamined Patent Application Publication No. Hei 7-135111
[Japanese Patent Document 3]
Japanese Unexamined Patent Application Publication No. Hei 7-169026
[Non-Patent Document 1]
Journal of Magnetism and Magnetic Materials, 93 (1991), pp. 58–66